NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Effects of inactivity on myosin heavy chain composition and size of rat soleus fibersMyosin heavy chain (MHC) and fiber size properties of the adult rat soleus were determined after 4-60 days of complete inactivity, i.e., lumbar spinal cord isolation. Soleus atrophy was rapid and progressive, i.e., 25% and 64% decrease in weight and 33% and 75% decrease in fiber size after 4 and 60 days of inactivity, respectively. Changes in MHC occurred at a slower rate than the atrophic response. After 15 days there was de novo expression of type IIx MHC (approximately 10%). By 60 days, type IIx MHC accounted for 33% of the total MHC content, and 7% of the fibers contained only type IIx MHC. The relative amount of type I MHC was reduced from 93% in control to 49% after 60 days of inactivity. Therefore, the effects of 60 days of inactivity suggest that during this time period at least 75% of fiber size and approximately 40% of type I MHC composition of the adult rat soleus can be attributed to activation-related events.
Document ID
20040172769
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Grossman, E. J.
(University of California Los Angeles 90095, United States)
Roy, R. R.
Talmadge, R. J.
Zhong, H.
Edgerton, V. R.
Date Acquired
August 22, 2013
Publication Date
March 1, 1998
Publication Information
Publication: Muscle & nerve
Volume: 21
Issue: 3
ISSN: 0148-639X
Subject Category
Life Sciences (General)
Funding Number(s)
CONTRACT_GRANT: NS16333
Distribution Limits
Public
Copyright
Other
Keywords
Non-NASA Center
NASA Discipline Musculoskeletal

Available Downloads

There are no available downloads for this record.
No Preview Available